1. Field of the Invention
The present invention relates to the technical field of liquid crystal display (LCD), and more particularly to an array substrate, an LCD device and a driving method.
2. Description of the Prior Art
So far the driving for each pixel unit in an array substrate of an LCD device may be achieved by: a voltage is applied on a pixel electrode which covers the pixel unit, so that an electric field is generated between a pixel electrode and a common electrode, and thus liquid crystal molecules in the pixel rotate for a certain angle, so as to transmit or block off lights.
The common electrode is configured for supplying a uniform common voltage V−com to all pixel units; the pixel electrode is configured for supplying a pixel voltage V−pixel to a corresponding pixel unit; and the voltage is configured for controlling an amount of light that transmits the pixel unit. When a frame of image is required to be displayed by the LCD device, a mode of line scanning (i.e. pixel units are turned on line by line, and the pixel units in a current line are turned off when the pixel units in a next line are about to be turned on) is usually applied. The pixel voltage is applied on the pixel electrodes when the pixel units are turned on, so that the display of the image is implemented.
During the process of implementing the display of the image by the electrical field between the pixel voltage and the uniform common voltage, if the pixel voltages of two pixel units in neighboring lines of a same column are different, the pixel electrode of the pixel unit that is turned on later is coupled to the common electrode, which may lead to the variation of the common voltage on the common electrode. As a result, the electrical field between the pixel electrode of the pixel unit that is turned on earlier and the common electrode varies, which results in a greenish phenomenon.
Furthermore, the pixel electrode is generally coupled to a drain electrode of a thin film transistor (TFT) in the corresponding pixel unit. The TFT is also turned off when the pixel unit is turned off. When the TFT is turned off, the pixel voltage on the pixel electrode gradually decreases as time elapses because of a leakage current and a parasitic capacitor, so that the voltage difference between the pixel electrode and the common electrode varies, which results in a flicker phenomenon.